Organise your defence into a diamond format (1 guard - 2 forwards - 1 center) 4v4 four half court game. The defence will double team as soon as the ball goes to the wing or the guard dribbles to the wing. In the first case it is the guard double teaming and in the second it is the forward coming for the double team. Double team everywhere in the quarter court except for the top of the key. Have your players rotating, talking, helping and pressing the ball (not for steals but for pass deflections - because the first gives you a lot of fouls).

Defensive Rotation, Help, Aggressiveness, Box Out, Reading and Reacting, etc.

This has proven useful so far, better than full court traps but it will never beat the good old fashioned man to man defence that is arguably the best defence to play and the best way to teach how to play.

You can also double team O1: have your player defending O1 cut off one side and double team either from the back or from the front (have signs ready...) You can adjust the shape of the zone defenses 3-2; 1-3-1; 2-3; etc. Players like it because it gives them the impression that you defend less time; which is in fact true but it is more aggressive, you take more chances, you make the game faster and more exciting.